Rolls for twist-drills.



S. DENK.

ROLLS POR TWIST DRILLS.

APPLIUATION FILED Nov. 29, 1912.

Patented Aug. 11, 1914.

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ROLLS FOR TWIST DRILLS.

APPLIOATION FILED NOV. 29, 1912.

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SIMON DENK, 0F BROOKLYN, NEW YORK.

ROLLS FOR TWIST-DRILLS.

To all whom it may concern Be it lrnown that l, SIMON DENK, a citizen of the United States, residing in Broollyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Rolls for Twistlrills, of which the following is a specification.

This invention has for its object to provide an improved device for forming twist drills by the operation of passing a rod or bar between apair of rolls, and which device can operate on a cylindrical drill rod to form .the helical grooves by forcing the Vmetal ahead as the blank passes between the rolls.

lrn the accompanying drawings, showing one embodiment of my invention, Figure 1 is a front elevation of the machine; Fig. 2 is an elevation, enlarged, of a portion of the machine, with the rolls and adjacent parts in section; Fig. 3 is an end elevation; Fig. 4 is a fragmentary view, showing the rolls in end elevation and a drill rod between the same; Fig. 5 is a view of one of the rolls; Fig. 6 is a fragmentary section, enlarged, of the adjacent portion of the rolls in one position with the drill `rod between the rolls; Fig. 7 is a fragmentary view, enlarged, showing the rolls in section at the beginning of the rolling operation; Figs. 8 and 9 are fragmentary sections 0f the adjacent portions of the roll at successively advanced positions from Fig. 7; Fig. 10 shows the rolls still further advanced in their rotation, and, Fig. 11 is a section of a drill as formed by the rolls.

The rolls, denoted generally by 11 and 12, are secured on driving `shafts 13 and 14, respectively, by anyl suitable means. A shaft 13 is shown as rotatable in standards 15 and 16, mounted on a base 17, the shaft having an extension 18 rotating in a standard 19, which extension also carries a driving pulley 20.

The shaft 14 is shown as rotatably mounted in the standards 15 and 16 parallel with the shafty 13; and suitable means are provided for rotating these shafts in unison and in opposite directions. A gear 21 on the shaft 14 engages the gear 22 on the shaft 13 to produce the desired relative rotation, and which gears are somewhat elongated to permit relative endwise movement of the shafts 13 and 14 for reasons hereinafter set forth. To secure the roll 11 on the shaft 13, the latter is shown provided with a threaded Specification of Letters Patent.

Application filed November 29, 1912.

Patented Amige 11, 1914. Serial No. 733,991.

bore 24 that engagesthe threaded extremity of a bar 25, and the latter has 'a tapered portion 26 that is made to fit the tapered bore 27 of the roll 11, and such parts are so arranged that upon screwing the bar 25 into the bore of the shaft 13, after the roll 11 has been slid on the tapered portion, the roll will engage the end of the shaft 13 and be forced to a very tight engagement with the bar 25, at the same time the latter is locked in the threaded bore of the shaft and forms a rigid extension there-of. The rear ends of the lbar 25 is supported in a standard 28 and thus forms an extension of the shaft 13. The roll 12 is similarly mounted on the shaft 14, having its tapered bore 30 engaging the tapered portion 13 of a bar 32; the latter being threaded on its forward end to screw into the threaded bore 33 of the shaft 14. The extension 32 of the shaft 14 also rotates in the standard 28. The rolls 11 and 12 are similarly formed but have their rod-engaging portions reversed for the reason that they rotate in opposite directions. The roll 11 is provided with a groove 34 that extends in a spiral or helical direction on the periphery of the roll, and the groove is shown as substantially circular in section, and the wall of the groove is preferably equidistant at all corresponding portions of the section throughout its position on the roll, The groove is shown as extending from a portion 35 on the roll to a portion 36 occupying the larger portion of the periphery, while a short portion, 37, on the periphery, is removed below the lowest point of the groove for the purpose of providing free admission of the drill rod, as indicated in Fig. 4. The other roll 12 is provided with a groove 38 similarly constructed, and this roll is provided with a reduced portion 39 corresponding with the reduced portion 37 of the other roll. These grooves 34 and 38 are so arranged on the two rolls that the turning of the rolls in opposite directions in unison, as by the said gears, will cause the grooves to register, as indicated in Figs. 2 and 7 The adjacent peripheral portions of the rolls 11 and 12, on each side of the grooves 34 and 38, are preferably caused to contact during this registering of the two grooves, that is, during engagement of the rolls between the reduced portions 37 and 39. rIhe roll 11 is shown as having a conical wall that extends on both sides of the groove 34, bein formed by helical portions 40 and 41; anc the roll.

12 is similarly constructed and provided with a conical face in the form of helical portions 42 and 43 on opposite sides of the groove 38, respectively. It is to be understood that these curved grooves are substantially semi circular and will inolose a eircular space as indicated in Fig. 7, that corresponds approximately with the cylindrical drill rod that is engaged by these two rolls. In the relative position, shown in Fig. 7, the rolls are in engagement on the sections A B of the two rolls, and upon rotating the rolls in th-e direction of the arrows in Fig. 4, the groove 34 would move to the right in Fig. 7, while the groove 38 would move to the left, and hence they would not register but travel away from each other. To overcome this objection the shafts 13 and 14 must be given an endwise relative movement and which must be equivalent to twice the pitch of one of these grooves. That is, if the groove 38 were to travel one inch axially in a revolution, and thus had a pitch of one inch, and the other groove had a similar pitch of one inch in the opposite direction, then these two shafts must be given an axial movement relative to each other of two inches for one complete revolution. It will vided with a spiralrib or cam 44 secured thereon and engaging rollers 45 and 1G on the base 17. The pitch of this cam is made double the pitch of the groove 34 whereby the proper endwise movement willv be imparted to the shaft 13 and the roll 11, to cause the grooves to remain .in register.

In the groove of each roll is a forming rib that will be forced into the drill rod to form its flute or spiral groove. The roll 11 is provided with a rib 47 that is arranged at one side of the curved groove 34; and this rib preferably starts at the section A-B, indicated in Fig. 4 and increases in altitude from the bottom of the groove, as indicated in the section of Fig. 9 which is j on the line E of Fig. 4, and reachesa maximum as indicated on the line 1--2 of Fig. 4, and as shown in Figs. 6 and 10. From this place on the roll the rib extends in the same form around to the reduced portion 39. It will be observed that the rib in. its maXif mum form is at one side of the groove and hence occupies about one-half of the groove. The other roll, 12, has ya similar groove 48 blank and start the formation of the grooves y therein, and during acontinuation of this drill-forming operation will` rollv the blank entirely between and entirelyout ofthe rolls. Duringthis .operation the elongation of the met-al, due to the forming of the grooves therein, operates tof lengthen the drill to some extent over the original of the blank therefor. During the rolling operation the drill blank not only travels forwardly but moves laterallvrelatively to the rolls in onedirection, and during that lateral movement (or movement of translation), turns upon its axis to the extent of the spirality or pitch of the drill grooves; and during this combined lateral and rolling` movement of the drill blank, the upper v roll has a movement longitudinal of its axis and in., the same direction tol twice the extent of the lateral movement of the* drill itself. In this manner the angular relation of the drill-forming surfaces, including the rib portion, in each of the-two rolls will be maintained throughout the entire operation without material variation.

The rolls may be further provided with means for forming a cutting edge at the forward edge of the flute, preferably by having the diameter of the drill lblank increased at this portion. Each of the grooves 34 and 38 where it engages the cylindrical surfacev of the drill. is recessed, the groove 34`having a recessed portion 51 adjacent the peripheral portion 40; while the groove 38 has a recessed portion. 52 adjacent the peripheral portion 42.- The channel between the rolls V11 and 12 will `beof less diameter than the drill rod `being passed therethrough `at all portions except at these narrow relcesses 51, 52 where the material of the drill is permitted to fill out and form, ribs 56 and 57, respectively, and leave a clearance 'onthe periphery of the drill back of these ribs 56 and'57.

It will be noticed that the line or plane at which the two rolls meet on both sides of the groove in the rolls containing lthe f rib. is at the cutting edge of the` drill rod as it is formed by the rolls. While the rolls are practically pressed together to engage4 'at these portions, a very slight clearance,

from spring of the shaft rolls, or slight play in the bearings, will take place that will result in avery thin extension or fin at the caused by the metal flowing out between the faces of the rolls adjacent the forming porn tions. 1t will be observed that this tin is right at the cutting edge of the drill andl forms a part of the projecting ribs 56 and 57 that are produced from the action of the recesses 51 and 52 in the rolls, respectively, where the curved portions of the grooves terminate in the engaging faces of the rolls. These cutting portions of the drill will normally need sharpening or grinding, and consequently these fins can be removed by such a process and at the same time result in a sharp cutting edge being formed in the edge of the drill.

My present improvements are especially intended for use in hot-rolling steel drill blanks into finished form excepting, as here# inbefore more fully explained, thegrinding off the thin fins at 54, 55 (Fig. 11), which constitute projecting edges from the ribs 56 and 57, as shown `by the lines of the drawing`1 in Fig. 6. Also, it will now be evident how the peculiar formations of the two co-acting rolls. with the groove-forming ribs, are located with one side thereof contiguous to, and ioining with. the roll faces. respectively, and how the peculiar formations serve to till out the required ribs 56, 57 on the cuttinofaces thereof by means of the lin-edges which are first formed and are later removed in the t-ruing up of the drill.

Having thus described my invention, 1 claim l. ln a device for rolling twist drills, a pair of rolls mounted on parallel axes, each roll having a helical groove which grooves extend in the same circumferential direction, each roll havinga rib located in the groove and at one side thereof contiguous to the roll face, means for rotating the rolls in unison in opposite directions, and means for effecting a relative endwise movement of the two rolls during rotation that is equivalent to double the pitch of said groove on one of the rolls` whereby the grooves will register at the adjacent portions of the rolls during the rotation of the rolls,\and the ribs will engage opposite portions of the drill rod to flute the rod. j

2. 1n a device for rolling twist drills, a pair of rolls mounted on parallel axes, each roll having a helical groove which grooves extend in the same circumferential direction, each roll having a rib located in the groove and at one side thereof contiguous to the roll face, means for rotating the rolls in unison in opposite directions, and means for eecting a relative endwise movement of the two rolls during rotation that is equivalent to double the pitch of'said groove on one of the rolls, whereby the grooves will register at the adjacent portions of the rolls during the rotation of the rolls, and the ribs will engage opposite portions of the drill rod to flute the rod, the rolls having their periphery on each side of the grooves conical and in engagement during rotation of the rolls in engagement with the drill rod.

3. In a device for rolling twist drills, a pair of rolls mounted on parallel axes, each roll having a helical groove which grooves extend in the same circumferential direction, each roll having a rib located in the groove and at one side thereof contiguous to the roll face, means for rotating the rolls in unison in opposite directions, and means for effecting a relative endwise movement of the two rolls during rotation that is equivalent to double the pitch of said groove on one of the rolls, whereby the grooves will register `at the adjacent portions of the rolls during t-he rotation of the rolls, and the ribs will engage opposite portions of the drill rod to flute the rod, the rolls having registering openportions for free admission of the drill rod', and the rolls having their peripheries on each side of the said grooves conical and in engagement during rotation ofthe rolls in engagement with the drill rod.

4. 1n a device for rolling twist drills, a pair of rolls mounted on parallel axes, each roll having a helical groove which grooves extend in the same circumferential direction, each roll having a rib located in the groove and at one side thereof contiguous to the roll face, means for rotating the rolls in unison in opposite directions, and means for effecting a relative endwise movement of the two rolls during rotation that is equivalent to double the pitch of said groove on one of the rolls, whereby the grooves will register at the adjacent portions of the rolls during the rotation of the rolls, and the ribs will engage opposite portions of the drill rod to flute the rod, the grooves in the rolls recessed on one edge to form a rib on the drill.

5. 1n a device for rolling twist drills, a pair of rolls mounted on parallel axes, each roll having a helical groove which grooves extend in the same circumferential direction, each roll having a rib located in the groove `and at one side thereof contiguous to the roll face, means for rotating the rolls in `unison in opposite directions, and means for effecting a relative endwise movement of the two rolls during rotation that is equivalent to double the pitch of said groove on one of the rolls, whereby the grooves will register at the adjacent portions of the rolls during the rotation of the rolls, and the ribs will engage opposite portions of the drill rod to finte the rod, the rolls having their periphery on each side of the grooves in engagement during rotation of the rolls in engagement with the drill rod, the grooves in rolls being recessed at one edge adjacent the periphery to form a rib on the drill.

6. 1n a roll for rolling a twist drill, a

member provided with a spiral groove eX- fending around its periphery, and a rib located in the groove at one side thereof and increasing in height for a short distance at its beginning, and thereupon continuing at the same height.

7. In a roll for rolling a twist drill, a member having a flattened portion at one part of' its periphery and a groove extending from the flattened portion spirally around the roll, and having a rib at one side of the groove, the groove startingl at the flat portion and increasing in height for a short distance and then continuing at 'the same elevation, the vroll surface on each side of' the grooved and ribbed portion being arranged conical.

8. In a roll for rolling a twist drill, a member having a flattened portion at one` part of its periphery and a groove extending 'from `the* flattened portion spirally varound the roll, and'having a rib at one side of' the groove, Ithe groove starting 'at the flat portion and increasing in height `for as'hort distance and fthen continuing at the same elevation, the roll surface on each side of the grooved and ribbed portion being arranged conical, the grooved portionon the side opposite the rib having a small recess adjacent the said conical portion.

9. ln a roll "for rolling a twist `1drill, a member provided with a spiral groove having a vrib at oneside ofthe groove,'and having a small channel at the other -side ofthe groove adjacent the periphery of the roll. SIMON DENK.

`Witnes`ses f Y FRED J. D ow,

JOHN MORRIS;

Copies oi this patent may be obtained for five centsreachpby addressingithe i Commissioner f Patents,

Washington, 1). C. n y 

